An emotive yet understated lead performance by Forest Whitaker bolsters this tale of a man's rise from plantation slave to revered White House butler. The good-natured intentions and powerful historical framing of Lee Daniels' movie manage to transcend the dramatic contrivances and distracting casting choices.

The Butler's storytelling scope is expansive if not consistently engrossing, charting the rise of black Americans during the 20th Century through the interconnecting fortunes of Whitaker's Cecil Gaines – based on real-life butler Eugene Allen. The civil rights movement, the black panthers and the Vietnam War all take their toll on Cecil and his family, while the plight to gain equality with white staff in the White House leads to much frustration. But can Cecil's calm demeanour lead to change in a world where many believe aggression is the route to positive change?

Forest Whitaker imbues Cecil with a vast amount of dignity and quiet resilience in the face of an abhorrent society that subjugates people based on skin color. One of his forlorn glances speaks more than a thousand words ever could. As his anxious wife Gloria, Oprah Winfrey issues a compelling reminder that she's a superb actress as well as a prominent celebrity.

David Oyelowo is also superb as their passionate, freedom-fighter son Louis, with the family's aging process over the decades proving to be incredibly successful due to aesthetically authentic make-up enhancements and delicate alterations in character mannerisms from the wonderful leads.

The clash of social changing methods between father and son, with their different approaches juxtaposed by Daniels' cross-cutting, certainly leads to many of the film's thematic triumphs. However, the verbal manifestations of the themes lack the same success as their visual depictions, for they are too explicitly stated in the dialog at times. Scriptwriter Danny Strong, who portrayed the nerdy sorcerer Jonathan Levinson on Buffy The Vampire Slayer, needs to bear in mind that audiences can think for themselves.

An awareness of the true story that this film was "inspired by" can severely detract from one's appreciation. The changes and embellishments made to the factual life story of Eugene Allen during the process of transforming him into the fictional Cecil Gaines do not sit easily alongside the archive news footage of many key historical events.

For these alterations, particularly one key moment that takes place in Cecil's childhood, reek of a calculating attempt to manufacture a procession of desired responses from the viewer - toying with their emotions and manipulating their sympathies with invention within the wider context of reality. It really wasn't required. The truth was powerful enough.

Trotting out a variety of well-known figures for small but important supporting roles may have helped to garner financing and publicity, but it often serves as an unwanted distraction from the unfolding narrative. Mariah Carey, so good when given a role of substance in Lee Daniels' Precious, is given little to do as Cecil's mother apart from cause the viewer to think 'that's Mariah Carey'.

Then there's the US Presidential version of Celebrity Stars In Your Eyes that unfolds, with the likes of Robin Williams, James Marsden, Alan Rickman and John Cusack donning various face-altering prosthetics to portray various incumbents of the White House. Again, it's an unnecessary distraction.

Despite these criticisms and its sporadic attempts to sabotage its own quest for credibility and veracity, The Butler provides a well-paced look at the fluctuating and often shocking socio-political landscape of the 20th Century, while also harnessing a moving, deeply personal narrative that's built upon the magic of Forest Whitaker's tremendous turn.